Newly planted Iris. When should I cut them back before winter.?

Question

The iris I planted in early September have started to get tall. They will not be able to bloom before winter. Should I cut them back now or wait until the first Frost?

Answer 1

A good rule of thumb is to allow the leaves to stay on the bulb as long as possible and try to wait until they've begun to lose their color before trimming them. The rhizomes are fed by the leaves, so if you let the leaves stay until they fall over and wilt, you'll know the bulbs are getting nutrition from them. If you need to trim them before they turn yellow, it won't hurt them, but the longer you can leave them, the better.

https://www.gardeningknowhow.com/ornamental/bulbs/iris/iris-plant-care.htm

https://www.gardeningknowhow.com/ornamental/bulbs/iris/dividing-transplanting-iris.htm